Help with oil catch can installment

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

soulpunisher

New Member
Joined
Apr 7, 2022
Messages
17
Reaction score
8
I need help with how to install an oil catch can. 2003 Jeep Liberty limited 3.7 4WD I see that there are 2 different hoses that plug into the air box? And the PCV valve that runs over the engine and into the oil filler neck/tube.
Can I do 2 different oil catch cans, one for the air box tubes and one one for the PCV? Or just one for only the other or what?
 

turblediesel

memberable
Joined
May 31, 2015
Messages
3,386
Reaction score
1,107
Location
Alaska
CRD owners often add a Provent air/oil seperator which has a drain tube that acts as an oil catch can. It's connected between the crankcase vent (hockey puck) and air inlet hose. No PCV on a CRD.
 

JRB

Full Access Member
Joined
May 27, 2021
Messages
263
Reaction score
263
Location
WPB, Florida
I know they are very popular for early model ls1 gm engines, I did on both of those cars I had in the past, it caught about 4 oz. every oil change. As those engines were notorious right from the factory gumming up the tb and intake, it's the only vehicle I've run catch cans on so far.

As others mentioned in between pcv and intake, and you probably thought of this, but choose the mounting location so its not a p.i.t.a. to drain (however your model drains) :D

The other tube looks like wouldn't be affected (look into it more just in case), but have little benefits as these vehicles don't seem seem to have that much getting by, and its not going somewhere that would foul up sensors and gum stuff up.

I'm curious if some run them and if these get enough oil in the vapors for it to be worth it to do, all this talk about catch cans now makes me want one again :)
 

soulpunisher

New Member
Joined
Apr 7, 2022
Messages
17
Reaction score
8
Well, my current solution is to get 2 oil catch cans. One of them having a 2 inlet and one outlet (internal breather and filter) I’ve done a lot of research and both hoses are crankcase valve breather inlets that plug into the air box next to the throttle body. I’m going to run both of those into the 2 inlet and one outlet catch can and run the one outlet hose into a custom cold air intake im going to install which has one inlet plug in only. Then do the standard catch can with 1 inlet and 1 outlet on the PCV by itself. Let me know what y’all think? As well as I intend on commenting the results of my idea/solution to let anyone else know if it is better/worth doing 2 cans. After doing valve cover gaskets change myself the PCV can is definitely needed! There was most definitely some sludge!
 
Last edited:

tommudd

Moderator
Staff member
Moderator
Joined
Jul 14, 2005
Messages
22,456
Reaction score
3,642
Location
Southeastern Ohio
Sludge comes from doing oil changes with too long intervals
cold air intakes do nothing on these motors

For further updates, I bought my 04 brand new, over 233,000 on it now and when I replaced valve cover gaskets at 198,000 clean as a pin, no sludge
My 03 I bought it with 75,000, had all service records , oil changes etc done every 5000
I do oil changes every 3500 full syn
did valve cover gaskets a few weeks ago at 175,000 and clean as a pin on it as well
so if OP has sludge, then it hasn't been taken very good care of
 

soulpunisher

New Member
Joined
Apr 7, 2022
Messages
17
Reaction score
8
On the contrary adding a cold air intake, especially a dual short ram air. Will not only free up a lot of space (from left and center) it will **** more and cleaner cold air in.. which is almost always better for almost anything that doesn’t have too many sensors to not let you do it lol.
I’d say it has sludge because the fact that the PCV valve on the model runs back into the oil filler neck!! Hence building/creating sludge no matter how well taken care of. Because it’s recirculating the inburnt oil, air etc back into the filler neck.. You may think yours is top notch, redo the gasket on the filler neck? (very easy and cheap) then tell me there’s not sludge in your engine at all?. It’s usually in the places you don’t think or haven’t looked. I thought this as well (above view view valve covers off looked very clean, looking through the filler neck hole there’s sludge working it’s way in and around the first quarter section)
These 3.7L are just notorious for gunking up, most would agree anyways.
 

rockymountain

Full Access Member
Joined
Apr 20, 2007
Messages
1,734
Reaction score
27
Location
Spencerville, IN
If you look at the stock air intake it is already a cold air intake. It scoops air from under the front of the hood. I don’t know why you would want to **** air from under the hood. Everyone that has been in here will disagree with you if you say a cold air intake will help anything on this engine. The is an intake air temp sensor that does quite a bit. That sludge you see is the notorious snot that forms due to the oil filler neck being cold in the winter. Short trips makes it worse, constant long drives over 30 minutes all the time, may never see it. It the same as when you go out in the cold and your nose starts running from the moisture in your breath. There is also a service bulletin that they use to change the pcv valve location and simplifies all the tubes. The 07s are setup this way already.
 

tommudd

Moderator
Staff member
Moderator
Joined
Jul 14, 2005
Messages
22,456
Reaction score
3,642
Location
Southeastern Ohio
On the contrary adding a cold air intake, especially a dual short ram air. Will not only free up a lot of space (from left and center) it will **** more and cleaner cold air in.. which is almost always better for almost anything that doesn’t have too many sensors to not let you do it lol.
I’d say it has sludge because the fact that the PCV valve on the model runs back into the oil filler neck!! Hence building/creating sludge no matter how well taken care of. Because it’s recirculating the inburnt oil, air etc back into the filler neck.. You may think yours is top notch, redo the gasket on the filler neck? (very easy and cheap) then tell me there’s not sludge in your engine at all?. It’s usually in the places you don’t think or haven’t looked. I thought this as well (above view view valve covers off looked very clean, looking through the filler neck hole there’s sludge working it’s way in and around the first quarter section)
These 3.7L are just notorious for gunking up, most would agree anyways.
Hot air su ck ers is all they are ( CAI )
Stock setup with a good paper filter will always do better than a CAI
Most all of us on here have been playing with these KJs for years now ( for me since 2004 ) and also ( 4x4s for close to 50 years )
we.ve seen what works, we've heard what works and doesn't work
CAIs do not
and what rockymountain stated is truse on the snot in the fill tube, short trips are a bigger issues than what you are talking about .
nortorious for gunking up LOL
and no most would not agree if taken care and ran properly
 

The gov

New Member
Joined
Jan 25, 2022
Messages
29
Reaction score
24
On the contrary adding a cold air intake, especially a dual short ram air. Will not only free up a lot of space (from left and center) it will **** more and cleaner cold air in.. which is almost always better for almost anything that doesn’t have too many sensors to not let you do it lol.
I’d say it has sludge because the fact that the PCV valve on the model runs back into the oil filler neck!! Hence building/creating sludge no matter how well taken care of. Because it’s recirculating the inburnt oil, air etc back into the filler neck.. You may think yours is top notch, redo the gasket on the filler neck? (very easy and cheap) then tell me there’s not sludge in your engine at all?. It’s usually in the places you don’t think or haven’t looked. I thought this as well (above view view valve covers off looked very clean, looking through the filler neck hole there’s sludge working it’s way in and around the first quarter section)
These 3.7L are just notorious for gunking up, most would agree anyways.
I myself am seeing a lot of 3.7's sludge up do to poor oil changes and poor oil had one lad here running 10w30 in a 2006 ... sludge was terrible, I did a varasol flush and put 5w30 high mileage synthetic in and replaced the PCV foam
seems to have worked well enough, the stock air filter is more than sufficient and filters way better than most aftermarket units which basically don't stop the finer dusts there by sand blasting your engine.. My own personal Liberty is long in the tooth with 348,000 klicks but doesn't burn any oil yet? nor sludge up oil changes are between 4500 to 5000 kms and transfer case and diffs get done once a year before the snow starts.
Good luck with your project and I hope that you can solve your issues!
 

soulpunisher

New Member
Joined
Apr 7, 2022
Messages
17
Reaction score
8
If you look at the stock air intake it is already a cold air intake. It scoops air from under the front of the hood. I don’t know why you would want to **** air from under the hood. Everyone that has been in here will disagree with you if you say a cold air intake will help anything on this engine. The is an intake air temp sensor that does quite a bit. That sludge you see is the notorious snot that forms due to the oil filler neck being cold in the winter. Short trips makes it worse, constant long drives over 30 minutes all the time, may never see it. It the same as when you go out in the cold and your nose starts running from the moisture in your breath. There is also a service bulletin that they use to change the pcv valve location and simplifies all the tubes. The 07s are setup this way already.
I’m going to run a longer piping behind the the passenger headlight (mine has custom wrangler headlights with a bypass to let cold air directly into the piping etc). Further more, I’m going to do this not only to switch from a square filter to a cone type k & n which usually gets better airflow (cone type) but to actually not have the hood mostly blocking what was almost a good idea until you see how much the hood blocks it, but there’s several other factors. Like a cleaner and easier type of piping to clean, a tighter fitting (the box that hooks directly to the throttle body has all kinds of seeping cracks etc and it’s just made that way which kind of defeats the purpose of steady flowing air?…) and to get more of the hoses for the air box run different directions that get them out of the way of almost everything. As well as free up most of the passenger side to get all that out of the way of your strut bolts and is even easier to get to the passenger side coil packs and fuel injectors/rail and to be able to clean to engine bay with much more ease and not really taking anything off etc.
not to mention I have almost all of this laying around already (piping,hoses, filter etc) to do it or the tools to customize just about anyway I want it. I personally have never heard anyone tell me for ANY vehicle that colder air and or tighter fittings (more consistent air flow) isn’t better for it?.. plus it isn’t gonna cost me anything except some time and work so why not? Oh, and mine is setup where there isn’t any sensors at all for the air intake. They are all on my manifold, so again why not do it? Plus way more room and easier cleaning all the way around is hard for anyone to say no to.
And I see what you’re saying about the oil filler neck and long/short runs and winter factors and if anything you’re giving more of a reason to install one? So that the Catch can, will CATCH it before running down the hose through the PCV valve and back into the filler neck… you do realize that’s what a PCV valve does, right? Any unburnt oil etc recirculates . This can cause sludge or rough idle and other things as well.
 

Latest posts

Members online

Top